The present invention relates to an image recording apparatus.
In one example of a prior art quality control system for a factory production line (manufacturing process), a visual sensor is arranged at a prescribed position of the production line to pick up images of the products conveyed on such production line, and then an image recognition process is carried out based on the image data picked up by the visual sensor to judge whether or not the imaged product is a conforming product. Then, in the case where the imaged product is judged to be a nonconforming product, such product is discarded. In this way, only conforming products are shipped out, and this makes it possible to guarantee the quality of the products.
On the other hand, in recent years, in the quality control and quality maintenance of the manufacturing process, attention has shifted from discarding nonconforming products that have been previously detected in a reliable manner to suppressing the generation of such nonconforming products. In order to do this, the cause of the generation of nonconforming products has to be identified, and then appropriate improvements to the production equipment need to be carried out. However, in the prior art system described above, even though it is possible to detect the generation of nonconforming products, it is difficult to identify the cause of the generation of such nonconforming products.
Namely, current visual sensors have a function to preserve image data used for inspection. However, the number of frames that can be recorded is small, and because the system is established only with a function to simply store images, it becomes difficult to accurately identify the cause of the generation of nonconforming products only by looking at the images used for inspection.
Further, in another prior art system, images that form inspection objects are outputted from a visual sensor and stored in an external image recording device. At such time, it is possible to also output inspection results from the I/O output of the visual sensor. Preferably, such I/O output (inspection results) is also stored in the image recording device in order to increase the data available for investigating the cause of the generation of nonconforming products.
However, because the I/O output and the image data are not obtained simultaneously in the visual sensor, they are outputted at their own respective timings. Accordingly, in the case where I/O data based on the generation of a nonconforming product is acquired, there is the case where the image data of such imaged nonconforming product has already been passed, or the reverse case where the image data has not been received yet. In other words, when the nonconforming product number is received, there are cases where the displayed image is an image having no relation to such nonconforming product. Accordingly, because the contact output of the I/O can not be stored in connection with the image data, it is not possible to effectively utilize such data, and this makes it difficult to identify the cause of the generation of nonconforming products.
In order to overcome this problem, a system has been developed in which a time stamp is added to each outputted data, and based on such time stamps at the time the outputs are played back, the system recognizes the time when each data was generated, and by carrying out control to match such data, synchronization can be carried out. However, adding a time stamp to each data makes the system complex and requires a large memory capacity, and if the tact number (the number of processes carried out per unit time) in the production line is increased, the amount of data processed per unit time will also increase. Consequently, the timing matching process based on the time stamps will not be able to keep up with all the data that needs to be processed, and this makes it impossible to carry out a playback process that achieves synchronization.
It is an object of the present invention to provide an image recording apparatus which makes it possible to connect and store related data (image data, inspection data corresponding to inspection results) for identifying the cause of the generation of nonconforming products.
The image recording apparatus according to the present invention is an apparatus for recording image data of an inspection object and inspection data corresponding to inspection results outputted at their own respective timings from an inspection device which judges quality by an image recognition process, and includes a temporary storage portion for temporarily storing the image data and the inspection data, storage means, and control means for synchronizing the image data and the inspection data and storing the synchronized image data and inspection data in the storage means based on relative position data from the prescribed signal sent from the inspection device, wherein the control means accesses the temporary storage portion to acquire previous data for at least the prescribed signal.
In this way, because synchronization of the image data and the inspection data can be achieved from shift amounts based on relative position data from the prescribed signal sent from the inspection device, there is no need for each data to hold time stamps, and this makes it possible to carry out high-speed processes. In this connection, the inspection data corresponding to the inspection results is data related to the inspection results, and in the embodiments of the present invention, this data corresponds to individual inspection results, measurement data and the like. Further, the prescribed signal sent from the inspection device is a characteristic signal of the inspection device which forms a reference signal, and in the embodiments of the present invention, this signal is a GATE signal, but it is also possible to use the step signal which forms the source of the GATE signal. Of course, other signals may be used so long as they can form a reference for obtaining relative position data.
Further, the storage means may be provided internally in the image recording apparatus, or the storage means may be an external storage means. Further, in the embodiments of the present invention, the inspection device corresponds to the visual sensor, the temporary storage portion corresponds to the ring buffer provided in the main memory, and the storage means corresponds to the storage device.
Now, in case where a new recording execution event occurs while data is being stored in the storage means, it is possible to omit the recording of the image data and store only the inspection data. In this way, it is possible to reliably store inspection data even when the speed at which data is written into the storage means is slow, for example.
Further, the image recording apparatus includes a display means, wherein a timing chart showing at least the timing of the acquired fields is displayed by the display means based on data stored in the temporary storage portion, wherein a prescribed position of the displayed timing chart is designated, and image data based on the designated position is displayed on the display means independently or overlaid on the timing chart, and wherein the control means is equipped with an initialization function to establish relative position data from the prescribed signal at the time when image data is being stored in the storage means based on the reception of an input which determines whether or not the displayed image should be stored in the storage means. In this way, because the relative position can be obtained visually, initialization can be carried out easily.
Further, the designation of the timing chart can be changed to field units. In this way, even in the case of a system where the images are inputted into the image recording apparatus by appropriately switching between signals from a plurality of imaging means, by carrying out a frame-by-frame transmission in field units, it is possible to reliably identify the switching timing position, and this makes it possible to accurately determine the relative position data.
Now, it should be noted that the structural elements of the present invention described above can be combined in any possible way. Further, each of the means used to construct the image recording apparatus according to the present invention can be achieved by exclusive hardware circuits or by a programmed computer.